Answer:
The "circulatory system" would belong to the level of organization known as an "Organ System."
A typical diagram of the circulatory system would show the heart, blood vessels, and blood flow. Here's a simple representation:
```
_________________
/ \
/ Heart \
/_____________________\
/ | \
/ | \
/ Arteries|Veins \
/____________________________\
/ \
/ \
/ Capillaries \
\ /
\______________________________/
```
In this diagram:
- The heart is shown as a central organ responsible for pumping blood.
- Arteries carry oxygen-rich blood away from the heart to various parts of the body.
- Veins carry oxygen-depleted blood back to the heart.
- Capillaries are the smallest blood vessels where gas exchange and nutrient exchange occur between blood and body tissues.
